WASHINGTON: The brother of the embattled State Department Inspector General quit as an adviser to Blackwater Worldwide, two days after the relationship with the security contractor was sharply criticized by a congressional oversight committee.

Erik Prince, Blackwater's top executive, said the conflict of interest questions raised by the connection prompted Alvin "Buzzy" Krongard to submit his resignation.

"I have reluctantly accepted it," Prince said in a statement Friday.

Alvin Krongard never received any payment for his work on Blackwater's advisory board, which only met once, Prince said.

"As far as I know, no allegations of impropriety have been lodged against Buzzy for his membership on our Board, and the publicized allegation of 'an apparent conflict of interest' against his brother Howard, with whom Buzzy has not been close for years, is just that, an allegation," Prince's statement said.

Due to the relationship, Howard Krongard was forced to step aside from any inquiries related to the company, a major State Department contractor and the subject of ongoing federal investigations.

However, the House Oversight and Government Reform Committee said Howard Krongard may have not answered truthfully about his brother's role with Blackwater and said it would continue to investigate.

Howard Krongard, who initially told the House Oversight and Government Reform Committee that his brother was not connected with Blackwater, was forced to step aside from any inquiries related to the company, a major State Department contractor and the subject of ongoing federal investigations.

According to information made public Friday by the committee, Alvin Krongard had told his brother well before the Nov. 14 hearing that he was becoming a strategic adviser to Blackwater.

"These discrepancies between the testimony of Howard Krongard and the information from Buzzy Krongard raise questions about the truthfulness of Howard Krongard's testimony," Waxman said in a memo to committee members.

The union that represents U.S. diplomats on Friday repeated its call for Krongard to step down.

"We still believe he should step aside temporarily until this issue has been fully resolved by the appropriate bodies," said John Naland, president of the American Foreign Service Association.

Waxman said he plans to invite the Krongard brothers to testify at a hearing to answer the questions.

If both appear, it's likely to be a chilly reunion. They are said not to be close and speak rarely.

Alvin Krongard called the committee Thursday after receiving a letter from Waxman seeking information about his connections to Blackwater and any communication he may have had with Howard Krongard about the company.

On Wednesday, Howard Krongard first told the committee his brother had no affiliation with Blackwater, calling such suggestions "ugly rumors." When confronted with evidence Alvin Krongard had joined Blackwater's advisory board, he called his brother during a hearing break and was told otherwise. He then informed the committee that due to the connection he would no longer be involved in any inquiries into Blackwater due to the apparent conflict of interest.

Alvin Krongard told the committee he was watching his brother testify on television and heard him say there was no Blackwater connection.

"You could have blown me over," Alvin Krongard told the committee.

Alvin Krongard recounted for the committee the conversation he had with his brother prior to the hearing.

"'He asked me whether I had any financial interest or any ties to Blackwater, and so I told him 'I'm going on their board,'" Alvin Krongard told the committee, according to Waxman's memo. "He responded by saying, 'Why would you do that?' and 'Are you sure that's a good idea?'"

It was his decision to make, Alvin Krongard told his brother, "and that we just differed on that," according to Waxman's memo.

The role of the advisory board is to offer "leadership advice" on the paths Blackwater should take to expand its business, according to the company.

Expenses for attending board meetings would be paid and board members would receive a $3,500 (¤2,388.92) honorarium for each meeting attended. The money could be paid to them or to a charity of their choice.

Blackwater spokeswoman Anne Tyrrell said the company saw no problem with inviting Alvin Krongard to join the board.

"No, we did not see a conflict of interest," she said. "I understand why Waxman made the connection, but if they dug a little deeper, they would see there is no conflict of interest there."

She said Alvin Krongard has requested that the payments he receives for attending board meetings be donated to a fund for CIA personnel killed in action and the Special Operations Warrior Foundation, a family support organization in Tampa, Florida.

In addition to recusing himself from matters related to Blackwater, Howard Krongard also said he is no longer involved in corruption investigations related to the flawed construction of the U.S. Embassy in Baghdad, a $600 million (¤409.53 million) project that is beset by logistical delays and security concerns.